Every little thing

While the dynamics, the kinematics if you will, of bicycles are a little beyond me, the mechanics are fairly well understood. I've been at it long enough and I have quite a lot of reference material without recourse to 'teh Internets', Sheldon Brown and so on. So when I'm asked what bottom bracket and chainset is needed for a vintage ten speed, of whose provenance I have no idea, or whether I can get away with running a V-Drive 22/32/44 and a roadie cassette and still maintain the sort of gearing range I'm used to, I can make informed guesses at worst, and straightforwardly find the answer at best. The only real problem I've seen is that the going rate for a bicycle mechanic, even a workshop manager, would mean a pay cut. One makes more money, presumably, by designing instead of maintaining. Maybe that's why in my gradually-falling-asleep-in-bed time, I come up with brilliant ideas for bicycle designs and modifications, but have no way to fabricate them.

Note to self: buy an oxy-acetylene kit, a lathe, a milling machine, and a bunch of tubes.

So when the idea occurs to junk the increasingly recalcitrant Sram Rocket Gripshifts on my Speedmachine and replace them with Shimano Rapid Fire triggers, it's perfectly easy. Whip off the handlebar grips, extract the gear cables, lose the Gripshifts, bung on the triggers, thread the gear cables back through, install that spare pair of handlebar grips left over from another project, and set up the dérailleurs again. Of course, this is my Speedmachine, that tour de force of Teutonic recumbency, and I should have known that nothing would be simple.

I already planned to replace the rear gear cable because the strands were unwinding and I wasn't sure if it was contributing to the poor gear changing where I'd been having to click down two and back up one to get onto the next largest sprocket. I've also generally disliked Gripshift, especially on upright bikes; I like my handlebar grips to stay in one place. On a recumbent bike where you place very little pressure on the handlebars, they work much better and are in fact one of the preferred systems, along with the brilliantly simple bar end gear lever. However, Shimano has traditionally used a 1:2 ratio of cable pulled to dérailleur movement, while Sram designed its components to use a 1:1 ratio which is more tolerant of squiffy alignment and mud-caked cabling -- but with the tradeoff that twice as much movement is needed at the handlebars, not generally a problem with the twisting action of Gripshift. And since my shifters were controlling Shimano front and back they had the 1:2 ratio, and it doesn't half make them hard work. I've been using Rapid Fire levers for nigh on 15 years on Annie the Blue Bike and the Rockhopper before it, so that was my intention for the Speedmachine. By way of reference, my P-38 uses bar end levers, while my V2 uses Gripshift but controlling a Sram rear dérallieur, and by and large, both systems work beautifully (until the 2500 mile mark at which one's P-38's rear cable will break -- a slight design flaw which I'm going to have a shot at fixing).

It wasn't long before I came up against the first hurdle: the curves of the handlebar, which give it a real handlebar moustache shape but actually designed for leaving space for one's knees when pedalling. The ideal position of the shifters was quite far inboard with the brake levers mounted to the outside: the opposite of what Gripshift dictates. The curves meant that the rinky-dink gear indicator on the top of the shifter stuck up at a rather silly -- and slightly knock prone -- angle, simply because Shimano designed it for flat handlebars. Then I discovered that the hydraulic hose to my brake lever wasn't long enough. Moving the shifter further inboard was an option, but then my knees would bash its lower trigger when I pedalled. I could extend the telescopic the stem towards my chest, but that would use up valuable millimetres of the hose length. Perhaps tilting the brake lever away from me would free up some of the length, as long as it was still comfortable to operate. But I couldn't tilt it very far without it trying to occupy the same space as the shifter, which I'd angled to be comfortable for my thumb and forefinger... So I decided that since I was a grown up cyclist, I'd remove the gear indicator and, not having the little grey bit of plastic that Shimano would have no doubt sold me at inflated cost, I improvised a cover with waterproof tape.

But extending the stem meant I now had to unpick all the tape and cable ties that oh so neatly tidied the two gear cable housings, the two large wires for my headlights, the wires for my headlight switch (which had to come off anyway because the other side's brake lever would need to go there), and the wires for my cycle computer's speed and cadence sensors. It was about 3ºC outside, and not much warmer in my garage, so this was all being done with a selection of numb fingers. Still, after about four hours I'd got the right-hand shifter in place, sans indicator gadget, plus the brake lever, I'd cut about a centimetre off the end of the handlebar to accommodate the grip (having first managed the impossible task of locating the pipe cutter) and the gear changing felt pretty good. So it was a straightforward job to repeat this for the left-hand side.

Hah. The Speedmachine has a very neatly routed front gear cable which runs down the outside (formerly the inside, until I changed it) of the stem, loops around below the headset bearing and then enters the boom of the frame. It runs forwards inside there and emerges, via a rather tight bend, from a hole just below the front dérailleur. I didn't like this at all: too much of a risk of kinking the cable housing and I was fairly sure this had happened and was making it harder than it should've been to change up to a bigger chainring. It got worse. I discovered the existing gear cable was equally kinked when I pulled it out, so I took out a new one. When I tried to install it, it went in halfway and stopped. I pulled and pushed again, it stopped and then kinked in front of my fingers. I tried again and it just wouldn't go in, and by this time the end was fraying as quickly as my sunny mood. So there was nothing for it but to replace the entire housing as well, and within moments I'd hauled it all out. It was kinked in two places and worn where it entered the frame. Fortunately I'd bought lots of spare housing last time around. To get new housing installed though, I had to remove the front half of the boom completely which wasn't something I'd do lightly because the plastic shim had already been cracked by the bike's original owner and when reinstalling the boom, it has to go back in exactly the same amount as it was before, otherwise you upset the distance to the pedals. And of course, it has to be straight.

Then I had an idea: left over from building my P-38 was one of those little curved steel tubes that are used on V-brakes to route the brake cable out and upwards; I could use that inside the boom to replace the tight bend! Well after an hour of trying, I decided it wasn't worth the effort. I could only insert the little tube from the outside, but since it wasn't attached to the cable housing -- it simply located the end of the housing, and used the cable itself to keep everything aligned -- the housing had to go in from the inside. That was more difficult because the boom was now in two halves. I threaded an old cable through in reverse to tie everything together but couldn't quite hold it while I reinserted the boom. And then I realised that once I installed the new gear cable, it wouldn't push the old one out at the end: it would just push the cable housing away from the little tube. Rant, rave, stomp, sigh.

'Right then', I growled to myself, 'I'll just do it the normal way after all.' And so it was that I managed to get new housing threaded through the two parts of the frame, the boom reinstalled and the new cable threaded through to the dérailleur, clamped in place and the excess chopped off. All that remained was to tidy up the cables and wires along the stem, and with a few cable ties and some more tape it was all about done. The last item on the agenda was to reattach the cadence sensor next to the crank and run the wire along the boom and up one one of the light's wires.

Naturally, I discovered I'd made too neat a job of tidying up, and didn't have enough length in the sensor wire to attach it in the right place and run it back to the stem as I wanted. When you're pedalling miles and miles with your thighs in very close proximity to delicate wiring, you pay attention to where you route your accessories. So I unpicked everything again, got the sensor in place and then little by little tidied up. Click click click, spin the pedals through the gears and tweak the cable tensions to perfection. Ta daa! Finished!

Well, almost. I hadn't ridden the bike since well before Christmas when the snow, and the salted grit, had arrived, and the water in the hosepipe had frozen solid. There was about a month of lightly festering salt crystals on the brake calipers and the rims were covered in grime, so today was the first chance to wash everything properly. I should have made do before, as I'd done with Annie while riding through the worst of the roads, with a bucket of hot soapy water and another to rinse. But I'd obviously been somewhere between lazy and preoccupied until now. The bucket was enough to clean up both Annie and the P-38 too, and it's really quite satisfying knowing that once again you've washed off all that nasty salt and grime.

I owe myself about £90 in bicycle mechanic time. I think that calls for a beer, don't you?